This application relates to a generator containment band having a coefficient of thermal expansion that is close to the coefficient of thermal expansion of the associated permanent magnets.
Generators are known, and typically include a source of drive driving a generator rotor. The generator rotor rotates in close proximity to a stator, and electricity is generated in the stator as the rotor rotates.
One type of rotor carries permanent magnets, and the rotation of these permanent magnets adjacent to windings in the stator create a magnetic flux that generates the electricity. It is desirable to have the magnetic flux be utilized as efficiently in the generation of electricity as is practical. Thus, components which may be mechanically necessary desirably do not limit the efficiency of the generation of electricity.
One type of rotor includes a containment band positioned radially outwardly of the permanent magnets, and which serves to hold the magnets onto the rotor. In the past, containment bands have desirably been thin, as they might otherwise reduce the efficiency of the flux interaction with the windings on the stator. On the other hand, the containment band must be strong enough to hold the permanent magnets, even against the high stresses that are encountered by high speed generator rotors.
Thus, very high strength materials have been utilized for the containment band, which has been unduly expensive.